Machine-switching telephone system.



'C. L. GOODRUM. MACHINE SWITCHING TELEPHONE SYSTEM. APPLICATION FlL-ED ocr. 6. I916.

Patented Dec. 18, 1917.

Charles L. aodl'bm oHARIEs'L; GOODR M, or BROOKLYN, NEW, Y0RK,1AssIGNoR TO wEsrEnn EtEoTRic' W COMPANY, INVCOBBORATEDL'PE NEW YORK, n. Y afoonrona'rron-or E YORK.

To all whom dandy/concern: ij

Be it known that I, CHARLES description.

This inventlon relatesto telephone ex-f change systems. employing machine switch j' and. front Contact vof relay2, conductor 47,

connector side-switchiarm 4:4: and its first Its obJect is to prov dea c rcuit arrange mentior systems of th s character wherein the calling party may ring'the bell of the calledparty after such party has replaced his receiver upon the switchhook at the ter-j ,mination of the conversation, l g 1 v In the circuit arrangement ofthis invention, the connector'is provided with a side switch which advances fromthe ringing to} v ringing Cut-oil "'relayfRCOf'When, howthe talking position upon the responseiof the called. party and connects, a magnet ,to a back contact of the stepping relay of the I connecton Iflwhen thecalled party hangs uphis receiver, the calling party desiresto l resignal such party,'he operates a switch associated with his substation set, which 'mo mentarilyv deenergizes the connectorTstep ping relay to close the circuit of sai'dmag-f net.. The magnet isprovidedwith-an armav ture which, whenaethated, resets the side- 1 switch from the talking position to the ring-f7 ing ,position,- whercupon the called line'isf the sender is operatingg fTherelay 1, in op- .erating,transmitsimpulsesto the magnet 4:6 I which stepsthefbrushe's 4, Sand 0 over the i again automatically signaled, the response;

of the called party causing thesideswi tch againto, advance tothe talkingposition.

:merical switch is setin motion, andasso-Ig ciates the calling line'with a-connector C, wwherupon the :stepping relay. ,1 thereat be-fi comes energized over, thejcalling line .eircuit,. and at its armature and frontcontact, enerj; .gizesa slow irelay 2. ;Relay 2, in, attracting, its'leftarmature, interposesla break in-tliea Figure l is a diagram of-a'circuitarrange ment embodying this inventlon and F 1g. 2 isa vside elevation, partlyinsection, ofthe,

modified sideswitch for-use-therewith.

; vThe invention will be readily understood 1 from a detailed description ofthe operation.

Upon the removal of the receiver at substation A, aline-finder or similar non-nu circuit of release magnet RM, and in attracting its right armature, connects the back contact -.ot'"zrel ay- :l' tent-he pr mary a stepping;

t t L. GroooR M, a citizen of the United States, residingat Brooklyn, in the countyof-Kings and State of New York, have invented'cert'ain' new" and useful Improvements .in Machine- Switching Telephone Systems, of which the: a following is a full, clear, concise, and exact a.

7 relation, to the group containing the called line terminals 7, '8 and '91: ground, armature MAcHINE sWIro ING"rELErHonE sYs'rEm; F

' Specification 6r Lettersratentl IPathted Dec;1S,1917. U Application,lile dioetolier ei aie f;ijs riai ntfia i,oe f' I V The calling party now operates h1s sender S totransmit the tens series of impulses. Each ti rne the" relay l retracts its armature, as" the sender S' in restoring to'normal interrupts the line circuit, an-impulse is transmitted 'over'the following circuit to magnet 3, to position the contact, magnet 3, free pole of battery.

"Upon the firstretraction of the armature of relay lea slow relay 43 becomesenergized and remains energized as the armature of frelay'l vibrates. Q-This" relay 43, inattracting its right" armature, energizes the sidesWit li'esjcape magnet te over a circuit in- "cluding'the armature and baclr'con tact of side jswitch intOfp SitionQ, In position 2,

the-arm tl'sub'stitutes secondary magnet-4 'in the stepping" ci rcu it for theprimary magnet g lhe'callirigfl party now operates his sender gS rt-o transmit the units digit of the called .,line., As' before, theslow relay l3 is energized upo'i1 jthe first retraction of the armaturejof relay 1,. and remainsenergiz'ed as selected igr up; Lana; into engagement with; mu'ltiples 7,8 and't} ofthe-calledliiie. vVilhen i the sender S -restores andm'aintainslthe" relay U '1 energized, [relay- 43 ,beeomes 'deenergized aftera slight interval, openinglthe circuit of the escape magnet l-t5,'which releases the side itohinto position Inpositioii- 3 relay 3 i in ene giz lev r-t e: follo ng vsire suitbto en g z e 'ape m gnet ap y ringing onrrentfto the ealled line: freepole o f battery, relay 4L3, conductors I10, 47', arm and} its third, contichfcondutor 11', 12, 1,3 to; ground at thearmature and front contact of relay. 1,; The 'attraction'jofthe right armatuijegof relay 43 energizes the escape magnet 45 which, in attracting its armature,

closes the ringing circuit as' follows free pole Qot battery- 15, or ringing generator llfi, de-

pending upon the position of the commutator 17, brush 18, relay lit-CO, armature and front contact oflnagnet 45, conductor 19, arm and its third contact, brush 5, multiple 8,

5 bell 22 at the substation B, 'condenser121,

multiple 7 brush 4, arm 23 and its third con- '20 t 28, right winding of relay 24 to'ground, In

position l of the side switch, side-switch arm 42 connectsinag'n'et l;9 to conductorfSO to Which is connected a front contact of the slow relay 2, which relay is now venergized 25 and'consequently the connection of thisrelay is extendedto the back'co'ntact of stepping relay 1. It will be noted that the circuit of the release magnet of the connector leads over the left armature and back contact of n I relay 2, and that therefore the control of the release of the connector'is' vested in the callpa'rtyf v If, now, the called party 'repla'c'es'his re ceiver, and the calling party desires to resignal such party, lie-operates hi sfsender S to interrupt the line circuit. This results in the energization of magnet 49 over the folcontact of relay 1, right armature and front switch arm 42 and its fourth contact, magnet attractive movement of the armature "32 is ust sufficient to set back'the side-switch arms a fromthefourth set of contacts c to are held, by the holding pawl m, engaging the tooth tof the ratchet rof'the side-switch 'escapemen t.

and whenf'the parties replace their receivers,

itWrYL ig b wind nso s t .RMir

y is closed forthe releasemagnet RM-ofthe' con'nectori ground, multiple *9, brush-'6, arm "38 and its second c0ntact,le'ft' a rnfatureand normal contact;- PON, conductors 34;, left armature and back contact of 'relay2, conductors 35, 86, left armature and' backbontact of relay 24, rlght a'r'maairean'd back contact of; relays 2 and 1 to ground. If the calling party replaces his receiver before the calledparty, the following circuit is'closerl to release the switches preceding the'con- "nector:*armature and back contact of relay 1, right armature and front contact of relay v 2, which, being slow, maintains its a-rmatures "attracted for an interval after the armature "of relay [1 reaches its "back contact,.conductors47, 37, left armature and front "contact.

of relay2l, conductor'36 to the test wire 50, jleading to therel'ease magnets of thepiefeeding switches. When thecalled party places his receiver,"'"rnagnet RM is energized over the following circuit: free poleofbaetery, windingof 'm'agn'etfRM, right armature and back-contact of relay '24, offnormal contact PON, conductor 34, left'art' mature;ancliback; 'coiitact of relay 2, con- I ductors' 35, 36,le'ft-ar1nature* aiidfback contact of relay i lfright]armaturesand'b-aclccontacts 'of relays 2 seal to ground.

Ifthe called line'is' busy,'the test -multiple 9 thereof is grounded, aha when'ithe test brush 6 is set thereon, the following circuit backcontact of relay 43,- conductor 34. 6011- j tact PON, right armature and backcont act of relay 24-,ri ght winding of relay RM free "pole of battery. The left armature' of "relay- 43 closes its-backc ont'act before the circuitfof the lowing circuit: ground, armature and back escape magnet 45 ,lea'dingover the right arma- Jture" of'said relay, isjop n'ednmgenough to 4c contact of relay 2, conductors'30, 31, sidecausethe 'deenergizatiofrof trees-cape magnet I f Therefore, the k'zirc'uit' traced "is closed over 9 to free pole battery. Magnet 49, in at f tracting its armature 32, (Fig. 1), moves the arm 48 thereon upwardly, causing such arm 45 to engage side-switch lever 33, the construe-1f tion and arrangement being such that the of inagnet RM, its armature "and frontc'ontact,jcoirductors 39,-40,*13,{to ground "at the armature and front contact 'of 'rel'ay 1; M'ag- 50 the third set, in which position such arms g V v V "calling line. "YVh'en-the calling party reiThe resetting of th-e side switch .to the 55' third position causes the closure of the "ringfling circuit traced, and upontherernoval of j the receiverjat substation B, "the relay BOO,

in 'deenergizing the escape magnetf'releases t V the side switch to position l'to open thering- 1 60 'ing circuit. The subscribers again converse,

n n ,7 I it wilPbe understood-that in practice. a-"conjth'e followi'ngcircuit is closedforthe release "Ina 'gnetBM jof' the connector}"free pole 3f la- 111 a' telephone -exchangeasysterrnethe 13o combination with telephone lines, automatic;

switches adapted to interconnect the same including a connector, a side switch for said connector, means operated by the, response of the called party for advancing said side switch from theringing to the talking position, and means controlled by the calling partly for resetting the sideswitchfrom the relay therefor, a senderadapted to interconnect said lines by means of said switches, a

side switch for said connector,means for to the talkingposition upon the response of the called party, and a magnet, means for connecting saidmagnet in the talking position of the side switch to a contact of the stepping relay, whereby, upon the operation of the sender in the talking position of the side switch, said magnet is arranged to reset the connector from the talking to the ringing position.

In a telephone exchange system, the combination with telephone lines, a connector, a side switch therefor, senders associated, with said lines adapted to set said connector on said lines, means for advancing said side switchfrom the ringing to the talking position upon the'response of the calledparty,

.a .magnet, said" side switch in its talking position connecting said magnet to a back contact of the stepping relay, and an armature carried by said magnet adapted to engage said side switch and. reset-the same from the talking to the; ringing position when said magnet isenergized.

4. In a telephone exchange system, the combination with telephone lines, means for interconnecting the same including an autoadvanclng said side swltch from the rmgmg matic switch, a side switch therefor, including a control magnet, means controlled by the calling party for setting said automatic switch on. a called line, an auxiliary magnet for said side switch, means for placlng the same under control of the calling party when said automatic switch isset, and means controlled by such party for operating said copies or this patent may be obtained for five tents each, by addressing the Commissioner of Patents.

Washington, D. G. a 

